LDAP_MEMCACHE(3LDAP) LDAP Library Functions LDAP_MEMCACHE(3LDAP)


NAME


ldap_memcache, ldap_memcache_init, ldap_memcache_set, ldap_memcache_get,
ldap_memcache_flush, ldap_memcache_destroy, ldap_memcache_update - LDAP
client caching functions

SYNOPSIS


cc -flag ... file...-lldap [ -library ... ]
#include <ldap.h>

int ldap_memcache_init(unsigned long ttl, unsigned long size,
char **baseDNs,struct ldap_thread_fns *thread_fns,
LDAPMemCache **cachep


int ldap_memcache_set(LDAP *ld, LDAPMemCache **cache


int ldap_memcache_get(LDAP *ld, LDAPMemCache **cachep


void ldap_memcache_flush(LDAPMemCache *cache, char *dn, int scope


void ldap_memcache_destroy(LDAPMemCache *cache


void ldap_memcache_update(LDAPMemCache *cache


DESCRIPTION


Use the ldap_memcache functions to maintain an in-memory client side
cache to store search requests. Caching improves performance and reduces
network bandwidth when a client makes repeated requests. The cache uses
search criteria as the key to the cached items. When you send a search
request, the cache checks the search criteria to determine if that
request has been previously stored . If the request was stored, the
search results are read from the cache.


Make a call to ldap_memcache_init() to create the in-memory client side
cache. The function passes back a pointer to an LDAPMemCache structure,
which represents the cache. Make a call to the ldap_memcache_set()
function to associate this cache with an LDAP connection handle, an LDAP
structure. ttl is the maximum amount of time (in seconds) that an item
can be cached. If a ttl value of 0 is passed, there is no limit to the
amount of time that an item can be cached. size is the maximum amount
of memory (in bytes) that the cache will consume. A zero value of size
means the cache has no size limit. baseDNS is an array of the base DN
strings representing the base DNs of the search requests you want
cached. If baseDNS is not NULL, only the search requests with the
specified base DNs will be cached. If baseDNS is NULL, all search
requests are cached. The thread_fns parameter takes an ldap_thread_fns
structure specifying the functions that you want used to ensure that the
cache is thread-safe. You should specify this if you have multiple
threads that are using the same connection handle and cache. If you are
not using multiple threads, pass NULL for this parameter.


ldap_memcache_set() associates an in-memory cache that you have already
created by calling the ldap_memcache_init() function with an LDAP
connection handle. The ld parameter should be the result of a successful
call to ldap_open(3LDAP). The cache parameter should be the result of a
cache created by the ldap_memcache_init() call. After you call this
function, search requests made over the specified LDAP connection will
use this cache. To disassociate the cache from the LDAP connection
handle, make a call to the ldap_bind(3LDAP) or ldap_bind(3LDAP) function.
Make a call to ldap_memcache_set() if you want to associate a cache with
multiple LDAP connection handles. For example, call the
ldap_memcache_get() function to get the cache associated with one
connection, then you can call this function and associate the cache with
another connection.


The ldap_memcache_get() function gets the cache associated with the
specified connection handle (LDAP structure). This cache is used by all
search requests made through that connection. When you call this
function, the function sets the cachep parameter as a pointer to the
LDAPMemCache structure that is associated with the connection handle.


ldap_memcache_flush() flushes search requests from the cache. If the base
DN of a search request is within the scope specified by the dn and scope
arguments, the search request is flushed from the cache. If no DN is
specified, the entire cache is flushed. The scope parameter, along with
the dn parameter, identifies the search requests that you want flushed
from the cache. This argument can have one of the following values:
LDAP_SCOPE_BASE
LDAP_SCOPE_ONELEVEL
LDAP_SCOPE_SUBTREE


ldap_memcache_destroy() frees the specified LDAPMemCache structure
pointed to by cache from memory. Call this function after you are done
working with a cache.


ldap_memcache_update() checks the cache for items that have expired and
removes them. This check is typically done as part of the way the cache
normally works. You do not need to call this function unless you want to
update the cache at this point in time. This function is only useful in
a multithreaded application, since it will not return until the cache is
destroyed.

PARAMETERS


ttl
The maximum amount of time (in seconds) that an item can be
cached


size
The maximum amount of memory (in bytes) that the cache
will consume.


baseDNs
An array of the base DN strings representing the base DNs
of the search requests you want cached


thread_fns
A pointer to the ldap_thread_fns structure structure.


cachep
A pointer to the LDAPMemCache structure


cache
The result of a cache created by the ldap_memcache_init()
call


ld
The result of a successful call to ldap_open(3LDAP)


dn
The search requests that you want flushed from the cache


scope
The search requests that you want flushed from the cache


ERRORS


The functions that have int return values return LDAP_SUCCESS if the
operation was successful. Otherwise, they return another LDAP error code.
See ldap_error(3LDAP) for a list of the LDAP error codes.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+

SEE ALSO


ldap_error(3LDAP), ldap_open(3LDAP), ldap_search(3LDAP), attributes(5)


April 9, 2016 LDAP_MEMCACHE(3LDAP)